1 files changed, 564 insertions, 0 deletions
diff --git a/contrib/llvm-project/clang/lib/StaticAnalyzer/Checkers/ExprInspectionChecker.cpp b/contrib/llvm-project/clang/lib/StaticAnalyzer/Checkers/ExprInspectionChecker.cpp
new file mode 100644
index 000000000000..3096999e9fd1
--- /dev/null
+++ b/contrib/llvm-project/clang/lib/StaticAnalyzer/Checkers/ExprInspectionChecker.cpp
@@ -0,0 +1,564 @@
+//==- ExprInspectionChecker.cpp - Used for regression tests ------*- C++ -*-==//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Analysis/IssueHash.h"
+#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
+#include "clang/StaticAnalyzer/Checkers/SValExplainer.h"
+#include "clang/StaticAnalyzer/Checkers/Taint.h"
+#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
+#include "clang/StaticAnalyzer/Core/Checker.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/DynamicExtent.h"
+#include "llvm/ADT/StringSwitch.h"
+#include "llvm/Support/ScopedPrinter.h"
+#include <optional>
+
+using namespace clang;
+using namespace ento;
+
+namespace {
+class ExprInspectionChecker
+    : public Checker<eval::Call, check::DeadSymbols, check::EndAnalysis> {
+  const BugType BT{this, "Checking analyzer assumptions", "debug"};
+
+  // These stats are per-analysis, not per-branch, hence they shouldn't
+  // stay inside the program state.
+  struct ReachedStat {
+    ExplodedNode *ExampleNode;
+    unsigned NumTimesReached;
+  };
+  mutable llvm::DenseMap<const CallExpr *, ReachedStat> ReachedStats;
+
+  void analyzerEval(const CallExpr *CE, CheckerContext &C) const;
+  void analyzerCheckInlined(const CallExpr *CE, CheckerContext &C) const;
+  void analyzerWarnIfReached(const CallExpr *CE, CheckerContext &C) const;
+  void analyzerNumTimesReached(const CallExpr *CE, CheckerContext &C) const;
+  void analyzerCrash(const CallExpr *CE, CheckerContext &C) const;
+  void analyzerWarnOnDeadSymbol(const CallExpr *CE, CheckerContext &C) const;
+  void analyzerValue(const CallExpr *CE, CheckerContext &C) const;
+  void analyzerDumpSValType(const CallExpr *CE, CheckerContext &C) const;
+  void analyzerDump(const CallExpr *CE, CheckerContext &C) const;
+  void analyzerExplain(const CallExpr *CE, CheckerContext &C) const;
+  void analyzerPrintState(const CallExpr *CE, CheckerContext &C) const;
+  void analyzerGetExtent(const CallExpr *CE, CheckerContext &C) const;
+  void analyzerDumpExtent(const CallExpr *CE, CheckerContext &C) const;
+  void analyzerDumpElementCount(const CallExpr *CE, CheckerContext &C) const;
+  void analyzerHashDump(const CallExpr *CE, CheckerContext &C) const;
+  void analyzerDenote(const CallExpr *CE, CheckerContext &C) const;
+  void analyzerExpress(const CallExpr *CE, CheckerContext &C) const;
+  void analyzerIsTainted(const CallExpr *CE, CheckerContext &C) const;
+
+  typedef void (ExprInspectionChecker::*FnCheck)(const CallExpr *,
+                                                 CheckerContext &C) const;
+
+  // Optional parameter `ExprVal` for expression value to be marked interesting.
+  ExplodedNode *reportBug(llvm::StringRef Msg, CheckerContext &C,
+                          std::optional<SVal> ExprVal = std::nullopt) const;
+  ExplodedNode *reportBug(llvm::StringRef Msg, BugReporter &BR, ExplodedNode *N,
+                          std::optional<SVal> ExprVal = std::nullopt) const;
+  template <typename T> void printAndReport(CheckerContext &C, T What) const;
+
+  const Expr *getArgExpr(const CallExpr *CE, CheckerContext &C) const;
+  const MemRegion *getArgRegion(const CallExpr *CE, CheckerContext &C) const;
+
+public:
+  bool evalCall(const CallEvent &Call, CheckerContext &C) const;
+  void checkDeadSymbols(SymbolReaper &SymReaper, CheckerContext &C) const;
+  void checkEndAnalysis(ExplodedGraph &G, BugReporter &BR,
+                        ExprEngine &Eng) const;
+};
+} // namespace
+
+REGISTER_SET_WITH_PROGRAMSTATE(MarkedSymbols, SymbolRef)
+REGISTER_MAP_WITH_PROGRAMSTATE(DenotedSymbols, SymbolRef, const StringLiteral *)
+
+bool ExprInspectionChecker::evalCall(const CallEvent &Call,
+                                     CheckerContext &C) const {
+  const auto *CE = dyn_cast_or_null<CallExpr>(Call.getOriginExpr());
+  if (!CE)
+    return false;
+
+  // These checks should have no effect on the surrounding environment
+  // (globals should not be invalidated, etc), hence the use of evalCall.
+  FnCheck Handler =
+      llvm::StringSwitch<FnCheck>(C.getCalleeName(CE))
+          .Case("clang_analyzer_eval", &ExprInspectionChecker::analyzerEval)
+          .Case("clang_analyzer_checkInlined",
+                &ExprInspectionChecker::analyzerCheckInlined)
+          .Case("clang_analyzer_crash", &ExprInspectionChecker::analyzerCrash)
+          .Case("clang_analyzer_warnIfReached",
+                &ExprInspectionChecker::analyzerWarnIfReached)
+          .Case("clang_analyzer_warnOnDeadSymbol",
+                &ExprInspectionChecker::analyzerWarnOnDeadSymbol)
+          .StartsWith("clang_analyzer_explain",
+                      &ExprInspectionChecker::analyzerExplain)
+          .Case("clang_analyzer_dumpExtent",
+                &ExprInspectionChecker::analyzerDumpExtent)
+          .Case("clang_analyzer_dumpElementCount",
+                &ExprInspectionChecker::analyzerDumpElementCount)
+          .Case("clang_analyzer_value", &ExprInspectionChecker::analyzerValue)
+          .StartsWith("clang_analyzer_dumpSvalType",
+                      &ExprInspectionChecker::analyzerDumpSValType)
+          .StartsWith("clang_analyzer_dump",
+                      &ExprInspectionChecker::analyzerDump)
+          .Case("clang_analyzer_getExtent",
+                &ExprInspectionChecker::analyzerGetExtent)
+          .Case("clang_analyzer_printState",
+                &ExprInspectionChecker::analyzerPrintState)
+          .Case("clang_analyzer_numTimesReached",
+                &ExprInspectionChecker::analyzerNumTimesReached)
+          .Case("clang_analyzer_hashDump",
+                &ExprInspectionChecker::analyzerHashDump)
+          .Case("clang_analyzer_denote", &ExprInspectionChecker::analyzerDenote)
+          .Case("clang_analyzer_express", // This also marks the argument as
+                                          // interesting.
+                &ExprInspectionChecker::analyzerExpress)
+          .StartsWith("clang_analyzer_isTainted",
+                      &ExprInspectionChecker::analyzerIsTainted)
+          .Default(nullptr);
+
+  if (!Handler)
+    return false;
+
+  (this->*Handler)(CE, C);
+  return true;
+}
+
+static const char *getArgumentValueString(const CallExpr *CE,
+                                          CheckerContext &C) {
+  if (CE->getNumArgs() == 0)
+    return "Missing assertion argument";
+
+  ExplodedNode *N = C.getPredecessor();
+  const LocationContext *LC = N->getLocationContext();
+  ProgramStateRef State = N->getState();
+
+  const Expr *Assertion = CE->getArg(0);
+  SVal AssertionVal = State->getSVal(Assertion, LC);
+
+  if (AssertionVal.isUndef())
+    return "UNDEFINED";
+
+  ProgramStateRef StTrue, StFalse;
+  std::tie(StTrue, StFalse) =
+      State->assume(AssertionVal.castAs<DefinedOrUnknownSVal>());
+
+  if (StTrue) {
+    if (StFalse)
+      return "UNKNOWN";
+    else
+      return "TRUE";
+  } else {
+    if (StFalse)
+      return "FALSE";
+    else
+      llvm_unreachable("Invalid constraint; neither true or false.");
+  }
+}
+
+ExplodedNode *
+ExprInspectionChecker::reportBug(llvm::StringRef Msg, CheckerContext &C,
+                                 std::optional<SVal> ExprVal) const {
+  ExplodedNode *N = C.generateNonFatalErrorNode();
+  reportBug(Msg, C.getBugReporter(), N, ExprVal);
+  return N;
+}
+
+ExplodedNode *
+ExprInspectionChecker::reportBug(llvm::StringRef Msg, BugReporter &BR,
+                                 ExplodedNode *N,
+                                 std::optional<SVal> ExprVal) const {
+  if (!N)
+    return nullptr;
+  auto R = std::make_unique<PathSensitiveBugReport>(BT, Msg, N);
+  if (ExprVal) {
+    R->markInteresting(*ExprVal);
+  }
+  BR.emitReport(std::move(R));
+  return N;
+}
+
+const Expr *ExprInspectionChecker::getArgExpr(const CallExpr *CE,
+                                              CheckerContext &C) const {
+  if (CE->getNumArgs() == 0) {
+    reportBug("Missing argument", C);
+    return nullptr;
+  }
+  return CE->getArg(0);
+}
+
+const MemRegion *ExprInspectionChecker::getArgRegion(const CallExpr *CE,
+                                                     CheckerContext &C) const {
+  const Expr *Arg = getArgExpr(CE, C);
+  if (!Arg)
+    return nullptr;
+
+  const MemRegion *MR = C.getSVal(Arg).getAsRegion();
+  if (!MR) {
+    reportBug("Cannot obtain the region", C);
+    return nullptr;
+  }
+
+  return MR;
+}
+
+void ExprInspectionChecker::analyzerEval(const CallExpr *CE,
+                                         CheckerContext &C) const {
+  const LocationContext *LC = C.getPredecessor()->getLocationContext();
+
+  // A specific instantiation of an inlined function may have more constrained
+  // values than can generally be assumed. Skip the check.
+  if (LC->getStackFrame()->getParent() != nullptr)
+    return;
+
+  reportBug(getArgumentValueString(CE, C), C);
+}
+
+void ExprInspectionChecker::analyzerWarnIfReached(const CallExpr *CE,
+                                                  CheckerContext &C) const {
+  reportBug("REACHABLE", C);
+}
+
+void ExprInspectionChecker::analyzerNumTimesReached(const CallExpr *CE,
+                                                    CheckerContext &C) const {
+  ++ReachedStats[CE].NumTimesReached;
+  if (!ReachedStats[CE].ExampleNode) {
+    // Later, in checkEndAnalysis, we'd throw a report against it.
+    ReachedStats[CE].ExampleNode = C.generateNonFatalErrorNode();
+  }
+}
+
+void ExprInspectionChecker::analyzerCheckInlined(const CallExpr *CE,
+                                                 CheckerContext &C) const {
+  const LocationContext *LC = C.getPredecessor()->getLocationContext();
+
+  // An inlined function could conceivably also be analyzed as a top-level
+  // function. We ignore this case and only emit a message (TRUE or FALSE)
+  // when we are analyzing it as an inlined function. This means that
+  // clang_analyzer_checkInlined(true) should always print TRUE, but
+  // clang_analyzer_checkInlined(false) should never actually print anything.
+  if (LC->getStackFrame()->getParent() == nullptr)
+    return;
+
+  reportBug(getArgumentValueString(CE, C), C);
+}
+
+void ExprInspectionChecker::analyzerExplain(const CallExpr *CE,
+                                            CheckerContext &C) const {
+  const Expr *Arg = getArgExpr(CE, C);
+  if (!Arg)
+    return;
+
+  SVal V = C.getSVal(Arg);
+  SValExplainer Ex(C.getASTContext());
+  reportBug(Ex.Visit(V), C);
+}
+
+static void printHelper(llvm::raw_svector_ostream &Out, CheckerContext &C,
+                        const llvm::APSInt &I) {
+  Out << I.getBitWidth() << (I.isUnsigned() ? "u:" : "s:");
+  Out << I;
+}
+
+static void printHelper(llvm::raw_svector_ostream &Out, CheckerContext &C,
+                        SymbolRef Sym) {
+  C.getConstraintManager().printValue(Out, C.getState(), Sym);
+}
+
+static void printHelper(llvm::raw_svector_ostream &Out, CheckerContext &C,
+                        SVal V) {
+  Out << V;
+}
+
+template <typename T>
+void ExprInspectionChecker::printAndReport(CheckerContext &C, T What) const {
+  llvm::SmallString<64> Str;
+  llvm::raw_svector_ostream OS(Str);
+  printHelper(OS, C, What);
+  reportBug(OS.str(), C);
+}
+
+void ExprInspectionChecker::analyzerValue(const CallExpr *CE,
+                                          CheckerContext &C) const {
+  const Expr *Arg = getArgExpr(CE, C);
+  if (!Arg)
+    return;
+
+  SVal V = C.getSVal(Arg);
+  if (const SymbolRef Sym = V.getAsSymbol())
+    printAndReport(C, Sym);
+  else if (const llvm::APSInt *I = V.getAsInteger())
+    printAndReport(C, *I);
+  else
+    reportBug("n/a", C);
+}
+
+void ExprInspectionChecker::analyzerDumpSValType(const CallExpr *CE,
+                                                 CheckerContext &C) const {
+  const Expr *Arg = getArgExpr(CE, C);
+  if (!Arg)
+    return;
+
+  QualType Ty = C.getSVal(Arg).getType(C.getASTContext());
+  reportBug(Ty.getAsString(), C);
+}
+
+void ExprInspectionChecker::analyzerDump(const CallExpr *CE,
+                                         CheckerContext &C) const {
+  const Expr *Arg = getArgExpr(CE, C);
+  if (!Arg)
+    return;
+
+  SVal V = C.getSVal(Arg);
+  printAndReport(C, V);
+}
+
+void ExprInspectionChecker::analyzerGetExtent(const CallExpr *CE,
+                                              CheckerContext &C) const {
+  const Expr *Arg = getArgExpr(CE, C);
+  if (!Arg)
+    return;
+
+  ProgramStateRef State = C.getState();
+  SVal Size = getDynamicExtentWithOffset(State, C.getSVal(Arg));
+
+  State = State->BindExpr(CE, C.getLocationContext(), Size);
+  C.addTransition(State);
+}
+
+void ExprInspectionChecker::analyzerDumpExtent(const CallExpr *CE,
+                                               CheckerContext &C) const {
+  const Expr *Arg = getArgExpr(CE, C);
+  if (!Arg)
+    return;
+
+  ProgramStateRef State = C.getState();
+  SVal Size = getDynamicExtentWithOffset(State, C.getSVal(Arg));
+  printAndReport(C, Size);
+}
+
+void ExprInspectionChecker::analyzerDumpElementCount(const CallExpr *CE,
+                                                     CheckerContext &C) const {
+  const MemRegion *MR = getArgRegion(CE, C);
+  if (!MR)
+    return;
+
+  QualType ElementTy;
+  if (const auto *TVR = MR->getAs<TypedValueRegion>()) {
+    ElementTy = TVR->getValueType();
+  } else {
+    ElementTy = MR->castAs<SymbolicRegion>()->getPointeeStaticType();
+  }
+
+  assert(!ElementTy->isPointerType());
+
+  DefinedOrUnknownSVal ElementCount = getDynamicElementCountWithOffset(
+      C.getState(), C.getSVal(getArgExpr(CE, C)), ElementTy);
+  printAndReport(C, ElementCount);
+}
+
+void ExprInspectionChecker::analyzerPrintState(const CallExpr *CE,
+                                               CheckerContext &C) const {
+  C.getState()->dump();
+}
+
+void ExprInspectionChecker::analyzerWarnOnDeadSymbol(const CallExpr *CE,
+                                                     CheckerContext &C) const {
+  const Expr *Arg = getArgExpr(CE, C);
+  if (!Arg)
+    return;
+
+  SVal Val = C.getSVal(Arg);
+  SymbolRef Sym = Val.getAsSymbol();
+  if (!Sym)
+    return;
+
+  ProgramStateRef State = C.getState();
+  State = State->add<MarkedSymbols>(Sym);
+  C.addTransition(State);
+}
+
+void ExprInspectionChecker::checkDeadSymbols(SymbolReaper &SymReaper,
+                                             CheckerContext &C) const {
+  ProgramStateRef State = C.getState();
+  const MarkedSymbolsTy &Syms = State->get<MarkedSymbols>();
+  ExplodedNode *N = C.getPredecessor();
+  for (SymbolRef Sym : Syms) {
+    if (!SymReaper.isDead(Sym))
+      continue;
+
+    // The non-fatal error node should be the same for all reports.
+    if (ExplodedNode *BugNode = reportBug("SYMBOL DEAD", C))
+      N = BugNode;
+    State = State->remove<MarkedSymbols>(Sym);
+  }
+
+  for (auto I : State->get<DenotedSymbols>()) {
+    SymbolRef Sym = I.first;
+    if (!SymReaper.isLive(Sym))
+      State = State->remove<DenotedSymbols>(Sym);
+  }
+
+  C.addTransition(State, N);
+}
+
+void ExprInspectionChecker::checkEndAnalysis(ExplodedGraph &G, BugReporter &BR,
+                                             ExprEngine &Eng) const {
+  for (auto Item : ReachedStats) {
+    unsigned NumTimesReached = Item.second.NumTimesReached;
+    ExplodedNode *N = Item.second.ExampleNode;
+
+    reportBug(llvm::to_string(NumTimesReached), BR, N);
+  }
+  ReachedStats.clear();
+}
+
+void ExprInspectionChecker::analyzerCrash(const CallExpr *CE,
+                                          CheckerContext &C) const {
+  LLVM_BUILTIN_TRAP;
+}
+
+void ExprInspectionChecker::analyzerHashDump(const CallExpr *CE,
+                                             CheckerContext &C) const {
+  const LangOptions &Opts = C.getLangOpts();
+  const SourceManager &SM = C.getSourceManager();
+  FullSourceLoc FL(CE->getArg(0)->getBeginLoc(), SM);
+  std::string HashContent =
+      getIssueString(FL, getCheckerName().getName(), "Category",
+                     C.getLocationContext()->getDecl(), Opts);
+
+  reportBug(HashContent, C);
+}
+
+void ExprInspectionChecker::analyzerDenote(const CallExpr *CE,
+                                           CheckerContext &C) const {
+  if (CE->getNumArgs() < 2) {
+    reportBug("clang_analyzer_denote() requires a symbol and a string literal",
+              C);
+    return;
+  }
+
+  SymbolRef Sym = C.getSVal(CE->getArg(0)).getAsSymbol();
+  if (!Sym) {
+    reportBug("Not a symbol", C);
+    return;
+  }
+
+  const auto *E = dyn_cast<StringLiteral>(CE->getArg(1)->IgnoreParenCasts());
+  if (!E) {
+    reportBug("Not a string literal", C);
+    return;
+  }
+
+  ProgramStateRef State = C.getState();
+
+  C.addTransition(C.getState()->set<DenotedSymbols>(Sym, E));
+}
+
+namespace {
+class SymbolExpressor
+    : public SymExprVisitor<SymbolExpressor, std::optional<std::string>> {
+  ProgramStateRef State;
+
+public:
+  SymbolExpressor(ProgramStateRef State) : State(State) {}
+
+  std::optional<std::string> lookup(const SymExpr *S) {
+    if (const StringLiteral *const *SLPtr = State->get<DenotedSymbols>(S)) {
+      const StringLiteral *SL = *SLPtr;
+      return std::string(SL->getBytes());
+    }
+    return std::nullopt;
+  }
+
+  std::optional<std::string> VisitSymExpr(const SymExpr *S) {
+    return lookup(S);
+  }
+
+  std::optional<std::string> VisitSymIntExpr(const SymIntExpr *S) {
+    if (std::optional<std::string> Str = lookup(S))
+      return Str;
+    if (std::optional<std::string> Str = Visit(S->getLHS()))
+      return (*Str + " " + BinaryOperator::getOpcodeStr(S->getOpcode()) + " " +
+              std::to_string(S->getRHS().getLimitedValue()) +
+              (S->getRHS().isUnsigned() ? "U" : ""))
+          .str();
+    return std::nullopt;
+  }
+
+  std::optional<std::string> VisitSymSymExpr(const SymSymExpr *S) {
+    if (std::optional<std::string> Str = lookup(S))
+      return Str;
+    if (std::optional<std::string> Str1 = Visit(S->getLHS()))
+      if (std::optional<std::string> Str2 = Visit(S->getRHS()))
+        return (*Str1 + " " + BinaryOperator::getOpcodeStr(S->getOpcode()) +
+                " " + *Str2)
+            .str();
+    return std::nullopt;
+  }
+
+  std::optional<std::string> VisitUnarySymExpr(const UnarySymExpr *S) {
+    if (std::optional<std::string> Str = lookup(S))
+      return Str;
+    if (std::optional<std::string> Str = Visit(S->getOperand()))
+      return (UnaryOperator::getOpcodeStr(S->getOpcode()) + *Str).str();
+    return std::nullopt;
+  }
+
+  std::optional<std::string> VisitSymbolCast(const SymbolCast *S) {
+    if (std::optional<std::string> Str = lookup(S))
+      return Str;
+    if (std::optional<std::string> Str = Visit(S->getOperand()))
+      return (Twine("(") + S->getType().getAsString() + ")" + *Str).str();
+    return std::nullopt;
+  }
+};
+} // namespace
+
+void ExprInspectionChecker::analyzerExpress(const CallExpr *CE,
+                                            CheckerContext &C) const {
+  const Expr *Arg = getArgExpr(CE, C);
+  if (!Arg)
+    return;
+
+  SVal ArgVal = C.getSVal(CE->getArg(0));
+  SymbolRef Sym = ArgVal.getAsSymbol();
+  if (!Sym) {
+    reportBug("Not a symbol", C, ArgVal);
+    return;
+  }
+
+  SymbolExpressor V(C.getState());
+  auto Str = V.Visit(Sym);
+  if (!Str) {
+    reportBug("Unable to express", C, ArgVal);
+    return;
+  }
+
+  reportBug(*Str, C, ArgVal);
+}
+
+void ExprInspectionChecker::analyzerIsTainted(const CallExpr *CE,
+                                              CheckerContext &C) const {
+  if (CE->getNumArgs() != 1) {
+    reportBug("clang_analyzer_isTainted() requires exactly one argument", C);
+    return;
+  }
+  const bool IsTainted =
+      taint::isTainted(C.getState(), CE->getArg(0), C.getLocationContext());
+  reportBug(IsTainted ? "YES" : "NO", C);
+}
+
+void ento::registerExprInspectionChecker(CheckerManager &Mgr) {
+  Mgr.registerChecker<ExprInspectionChecker>();
+}
+
+bool ento::shouldRegisterExprInspectionChecker(const CheckerManager &mgr) {
+  return true;
+}